Does prediction error during exposure relate to clinical outcomes in cognitive behavior therapy for social anxiety...

Exposure therapy is an effective treatment for anxiety disorders, but its mechanisms remain unclear. We explored the violation of threat-predictions during exposure, which has been hypothesized as necessary for symptom change. Forty-three adults undergoing exposure therapy for social anxiety disorder recorded their experiences during 523 in- and between-session exposures by completing smartphone surveys. Participants rated their threat-predictions, threat-outcomes, anxiety levels, surprise, and learning outcome for each exposure. We used multilevel models to explore the effect of prediction error (threat-prediction from outcome) during exposure on anxiety symptoms at the next session, and on symptom change from baseline to three months follow-up. Exposures successfully generated threat-prediction error and unexpected exposure outcomes were experienced as more surprising and likely to stimulate learning. However, larger threat-prediction error during exposure did not predict lower symptoms at the next session, nor overall symptom improvement. These findings suggest that the magnitude of threat-prediction error is not, in itself, sufficient for successful exposure therapy.